Electrical switching device



April 23; 1935. v. 1.. RONCI ET AL ELECTRICAL SWITCHING DEVICE Filed June 1, 1935 FIG. 2

I MLRONC/ lNl/ENTORS E E ELBERT 8V 2 Maw/U 6. M

ATTORNEY Patented Apr. 23, 1935 UNITED sr T-Es PATENT OFFICE ELECTRICAL SWITCHING DEVICE Victor L. Ronci and Edward F. Elbert, Brooklyn,

. N. Y., assignors to Bell Telephone Laboratories,

' Incorporated,;New York, N. Y., a corporation of New York Application June 1, 1933. Serial No. erases w v 1 Claims. ((1200-87) Thisinvention relates to "electrical switching portions of the contact assemblies of the device devices and more particularly to such. devices in shown in Fig. -1; and which the contactsare operated in'anevacuated Fig. 3 is an enlarged perspective view of the chamber. movable contact showing in detail the shape of One object of this. invention to preventiarcthe groove in the contact and the relationship of 5 ,ing between the contacts in electrical switching the dislocated contact to the guide supports. devices which are adapted for use in high voltage Referring now to the drawing, the switching circuits. a v I. device of this invention includes a vitreous en,- Another object of the invention is to provide closing vessel having a bulbous portion l0 and a switching device which will be eifective in rean elongatedtubular portion H,.the vessel pref- 10 duced atmosphere such as at high altitudes. erably being highly evacuated; Aflmetflllic l In one embodiment ofvthis invention, a Witch terminal I2 is mounted on an insulating disc l3 'ing device comprises a pair of normallyopen conandis secured to the bulbous portion l0, and a tacts supported in operative relationin a vessel, similar metallic cap or terminal M is secured to which may be highly evacuated. One of the conthe tubular portion H. The tubular portion H 15 tacts is movable and is actuable by an electrois provided with a reentrant stem IS in which magnet supported externally of the vessel. there is embedded a metallic rod N which is elec- A feature of this invention relates to a subtrically C nn o h p 1 terminal I4 and stantially;non-frictional guiding support for the has secured to one end thereof "a contact ll, of movable contact assembly. tungsten orthelike. A metallic member 18, which 20 Other features of this. invention relate to a may be of a magnetic material such as iron; and shock-absorbing mounting for a contact point in may be c om u plated 0 prevent Corrosion the body of the movable contact. assembly to thereOL-hasvan integral annular shoulder 5| of eliminate sparking upon the closure'of the con l y greater height than the'contact is tacts and'to a movable contact assembly of large mounted upo the d s and is provided at 0118 2:5 mass which serves as a gravity-actuated member endwith a recess in which the contact I! is seated. to break the engagement between the, contacts The member I8 is preferably of appreciable mass quickly upon deenergizingof the electromagnet. and prevents excessive jarring of the contact I! A further feature of. this invention. relates toa during the p ratio f h swi h d vi novel support for the electromagnet exteriorly of The bulbous portion I 0 is provided with a re- 30 the vessel, comprising a collar. having aplurallty entrant stemv l9 terminating in a press 20 in of fingers to, engage a tubular core carryin'gthe which a pair of rigid parallel guides or rods electromagnet winding. Y 2| 'are embedded. The rods 2| extend within Further features of this invention relate: to a the tubular portion H and are spaced and interretractile spring for restoring the movable connn d by a be t p O 'S P A movtact to its normal or open 'position and to the able contact assembly is disposed between the provision of a non inductive current carrying rods 2| and'includes a cylindrical mass or body flexible link member of negligible tension conmember 230i a magne i material, Such as iron, nected to. the movable contact, whereby the use having a pa of diametrically d p p d 0 of the retractile spring as a current conductor is guide gro 24 in its. Outer ud a ce 40 obviated and deterioration of the springisfprefor accommodating thevlods 2L c Of he vented. shape of the grooves a relatively'small contact The invention and the various features thereof Surface exists between the rods and the y 111 e understood el and fully m 23 so that a very small frictional force is present the following detailed description with reference when the body moves along the rods- The rods 45 to the accompanying drawing in which: grohves are so disposed that the body Fig. 1 is a perspective view of an 'electr 'tal 15 in axlal alignment Wmhthe mass member switching device illustrative of this invention, g g i ggg g g pg i ig gfi g z gg i with the electromagnet in cross-section, with g 1 means for. securing the electromagnet and device mg Surface m the grooves of very low frictlon 5O and is rovided with an axial bor throu i together. Portions of the'enclosmg vessel are a rod extemm A Contact whichg g broken away to show the contact assemblies more of t g t is unt d upon one end of the clearly; rod 25, and a collar or button 21 is secured to Fig. 2 is an-enlarged view in cross-section of the rod adjacent the other end thereof and abuts 55 against one end of the body 23 as shown in Fig. 2. A helical spring 28 is disposed within the bore in the body 23 and abuts at one end against the contact 26 and at the other end against a shoulder or seat 29 within the body 23.

The rod is connected at the end toward stem iii to a retractile spring 30 secured to a bent wire embedded in the press 20. A non-inductive conductor such as a folded flexible ribbon or spring 32 is connected at one end of the rod 25 and at the other end to a stub or short wire 56 embedded in the press 20 and electrically connected to the terminal I2 by a conductor 33. The folded flexible member or spring 32 obviates the use of the retractile spring 30 as a current carrying member so that deterioration of the spring 33, which might result from a current fiow therethrough, is prevented.

A collar or support is secured about the bulbous portion I9 and comprises two similar semicylindrica-l portions 34, each having a plurality of fingers 35 extending parallel with and toward the tubular portion ll of the vessel from one end of the collar. The collar is also provided with juxtaposed flanges 36 through which bolts 3i extend. An electromagnet is coupled to the collar, and comprises an annular coil 38 which encircles a tube or core 39 of non-magnetic material, for example, brass,'adapted to encircle the tubular portion H of the enclosing vessel. The ends of the tube or core 39 are spun over annular plates 46 of magnetic material, for example, iron, disposed adjacent the bases of the coil 38 and spaced therefrom by insulators M. A flanged tubular member 42 of non-magnetic material is secured in any convenient manner, for example, by rivets 43, to one of the plates and is adapted to fit within the fingers 35 and may be clamped in position by a band or collar :4 which encircles the fingers 35. An insulating block 45, on which terminals 48 for the coil 38 are mounted, is secured to the end plates 40 by eyelets 7. The plates 40 are provided with extensions or lugs 49 through which the switching device may be secured to a suitable support.

The operation of the switching device in an electrical circuit is as follows: Normally, the contacts I! and 25 of the switching device are spaced apart as indicated in Fig. 2, and the movable mass or body 23 rests upon or abuts against the strap or stop 22. .When it is desired to close circuit, the coil 38 is energized from a suitable source and the magnetic field produced acts upon the body 23 and causes it to move toward the stationary member l8 against the tension of the retractile spring 3!]. Inasmuch as the member i8 is of appreciable mass an efficient magnetic circuit is provided. The movement of the body brings the contact 26 into engagement with the contact 5?, the spring 28 acting as a buffer or cushion to prevent jarring of the contacts I! and and also to maintain a good engagement between the contacts so that arcing is prevented. The shoulder prevents excessive depression of he contact 26 relative to the body member 23. When the coil 38 is deenergized, the member moves away from the stationary member [8 through the action of the spring 30 and the engagement between the contacts I! and 2B is broken. Inasmuch as the body 23 is of appreciable mass, if the switching device is supported vertically in the position shown in Fig. 1, the gravitational force is relatively great and a quick break between the contacts I! and 26 is obtained so that arcing between the contacts is prevented. The movement of the body 23 away from the stationary contact assembly is limited by the strap or stop 22.

Since the contacts operate in a high vacuum, arcing or fiashover is prevented. Furthermore, the operating characteristics of the switching device are independent of external conditions so that the device is particularly suitable for use in apparatus, for example, radio apparatus or aircraft, which may be operated in rarefied atmospheres at high altitudes as well as in approximately normal atmospheres.

It will be understood, of course, that many modifications may be made in the embodiment of the invention shown and described without departing from the scope and spirit of this invention as defined in the appended claims.

What is claimed is:

1. An electrical switching device comprising an enclosing vessel, a plurality of assemblies having contacts thereon mounted in cooperative relation within said vessel, one of said assemblies being movable, means for actuating said movable contact, and a plurality of guide members engaging spaced portions only of said movable assembly for aligning the contact thereon with respect to another of said contacts, said movable assembly including means cooperating with said guide members to prevent rotation of said movable assembly.

2. An electrical switching device comprising an enclosing vessel, a stationary contact within said vessel, a movable contact assembly within said vessel including a body member and a contact on said body member, means for actuating said movable assembly, and a plurality of guide members engaging only spaced limited portions of the outer surface of said body member and aligning the movable contact with respect to said stationary contact.

3. An electrical switching device comprising an enclosing vessel having a stem, a stationary contact within said vessel, a movable contact assembly in alignment with said stationary contact including a body member having a plurality of iongitudinal grooves in its outer surface, means for actuating said contact assembly, and a. plurality of guide members extending from said stem and in contact with walls of said grooves.

4. An electrical switching device comprising an enclosing vessel, a stationary contact within said vessel, a movable contact adjacent said stationary contact, and means exterior to said vessel for actuating said movable contact including a tubular member encircling said vessel, a magnetic coil surrounding said tubular member, a collar about said vessel having projections engaging said tubular member, and means clamping said projections against said tubular member.

5. An electrical switching device comprising an enclosing vessel of insulating material, a plurality of contacts within said vessel, one of said contacts being movable, a terminal on said vessel, a retractile spring fixed at one end to said vessel and connected at the other end to said movable contact, and means insulated from said spring at one end by said vessel and electrically connecting said movable contact to said terminal.

6. An electrical switching device comprising an enclosing vessel of insulating material, a stationary contact within said vessel, a movable contact in cooperative relation with said stationary contact, metallic guiding means for said movable contact, a retractile spring coupled to said movable contact and to said vessel, and a tallic rods embedded in said stem, a metallic member held in said stem and terminating therein, a retractile spring coupled to said movable contact and to said metallic member, and an electrical connection between said movable contact and said stem including a folded metallic ribbon. a

8. An electrical switching device comprising an enclosing vessel, a stationary contact within said vessel, a movable assembly including a body portion having an aperture therein, guide members engaging said body portion, a plurality of resilient members each fixed at one end and connected to said assembly, only one of said members senving as a lead-in conductor for said assembly, a contact member within said aperture and disposed in cooperative relation to said stationary contact, and cushioning means within said aperture engaging said body portion and said second contact.

9.. An electrical switching device comprising an enclosing vessel having a stem, a stationary contact within said vessel, a plurality of rods extending from said stem, a magnetic member slidably mounted on said rods, a stop member on said rods adjacent one end 01 said magnetic member, a retractile spring connected to said stem and to said magnetic member, an electromagnet exterior of said vessel adapted to propel said magnetic member along said rods, and a contact resiliently mounted on said member and disposed in cooperative relation with said stationary contact.

10. An electrical switching device comprising an enclosing vessel having a stem, a stationary contact within said vessel, a plurality of guide members extending from said stem, a magnetic member having an aperture therein and a plurality of grooves into which said guide members extend, a rod extending through said aperture having a collar at one end abutting against said magnetic member, a contact mounted on said rod and disposed adjacent said stationary contact, a helical'spring within said aperture engaging said second contact and said magnetic member, an electromagnet adapted to move said magnetic member along said guide members, and a retractilespring coupled to said rod and to said stem.

11. An electrical switching device comprising an enclosing vessel having a stem at each end thereof, a stationary contact mounted on one stem, a plurality of parallel rods extending from the other stern, a terminal on said vessel, a'magnetic member of relatively large mass disposed in alignment with said stationary contact and having grooves the walls of which are engaged by said rods, a contact resiliently mounted on said magnetic member and disposed adjacent said stationary contact, an electromagnet surrounding said magnetic member, a retractile spring coupled to said magnetic member and to said stem, and a resilient conductor electrically connected to said second contact and to said terminal, said conductor forming the sole leadingin connection to said second contact.

VICTOR. L. RONCI.

EDWARD F. ELBERT. 

